A greasy white substance called vernix caseosa coats her entire body to protect her skin during its long submersion in amniotic fluid. (This slick coating also eases the journey down the birth canal.)
Your baby is swallowing more, which is good practice for her digestive system. She's also producing meconium, a black, sticky substance that's the result of cell loss, digestive secretion, and swallowed amniotic fluid. This meconium will accumulate in her bowels, and you'll see it in her first messy diaper (although a few babies pass it in utero or during delivery).